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Discussion Starter #1
Can anyone please help me with a problem i have with my 1986 4.1 Fwd deville.I live in Nottingham , Great Britain, so there isn`t many people here who know there stuff about these caddys. It seems to have an engine knock when sitting in traffic, when it`s driving its ok ,engine coolant temp is around 75 - 80 degrees centigrade, when in traffic the temp rises to around 105 degrees centigrade and the knocking starts, damn car has no temp gauge!! had to use the diagnosis to find the temp out. What temp is the car supposed to run at?? should the fans kick in before the 105 degrees mark?? What controls the fans??can`t find a fan switch! hope u can help!! Matt
 

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1989 Sedan DeVille is now just a fond memory ....
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I'm not sure what the metric numbers should be in regard to eingine temp but it suonds like you are getting a bit hot while slow moving. That should not be a problem if the coolong system is in proper shape. When is the last time the coolant was replaced?

You should consider draining and refilling with new coolant. You should also check for blockage or leaks. Has the coolant level remained constant or have you had to add?
 

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01 frontier , 89 Shelby CSX vnt
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your running at 221 degrees , which is fairly normal for these engines
http://www.wbuf.noaa.gov/tempfc.htm

running premium fuel ?
egr tubes clear and egr valve working properly ?

engine temperature will aggrivate these issues into a ping or knock , as it sends the combustion temps higher than the poorly operateing EGR or whatever is causeing your ping can compensate for ...these engines dont have knock sensors so it has no idea it needs to take a few degrees out of the ignition timing to keep it from pinging
 

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Discussion Starter #4
Thanks for the help. I`m thinking of taking the engine out sometime in the future and replacing the cam and the main bearings etc, can these engines come out while leaving the transmission in the car??
 
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